
const DEFAULT_CONFIG = {
  id: "id",
  children: "children",
  pid: "pid",
};
export const defaultProps = {
  children: "children",
  label: "name",
  value: "id",
  isLeaf: "leaf",
  emitPath: false, // 用于 cascader 组件：在选中节点改变时，是否返回由该节点所在的各级菜单的值所组成的数组，若设置 false，则只返回该节点的值
};

const getConfig = (config) => Object.assign({}, DEFAULT_CONFIG, config);

// tree from list
export const listToTree = (list, config = {}) => {
  const conf = getConfig(config);
  const nodeMap = new Map();
  const result = [];
  const { id, children, pid } = conf;

  for (const node of list) {
    node[children] = node[children] || [];
    nodeMap.set(node[id], node);
  }
  for (const node of list) {
    const parent = nodeMap.get(node[pid]);
    (parent ? parent.children : result).push(node);
  }
  return result;
};

export const treeToList = (tree, config = {}) => {
  config = getConfig(config);
  const { children } = config;
  const result = [...tree];
  for (let i = 0; i < result.length; i++) {
    if (!result[i][children]) continue;
    result.splice(i + 1, 0, ...result[i][children]);
  }
  return result;
};

export const findNode = (tree, func, config = {}) => {
  config = getConfig(config);
  const { children } = config;
  const list = [...tree];
  for (const node of list) {
    if (func(node)) return node;
    node[children] && list.push(...node[children]);
  }
  return null;
};

export const findNodeAll = (tree, func, config = {}) => {
  config = getConfig(config);
  const { children } = config;
  const list = [...tree];
  const result = [];
  for (const node of list) {
    func(node) && result.push(node);
    node[children] && list.push(...node[children]);
  }
  return result;
};

export const findPath = (tree, func, config = {}) => {
  config = getConfig(config);
  const path = [];
  const list = [...tree];
  const visitedSet = new Set();
  const { children } = config;
  while (list.length) {
    const node = list[0];
    if (visitedSet.has(node)) {
      path.pop();
      list.shift();
    } else {
      visitedSet.add(node);
      node[children] && list.unshift(...node[children]);
      path.push(node);
      if (func(node)) {
        return path;
      }
    }
  }
  return null;
};

export const findPathAll = (tree, func, config = {}) => {
  config = getConfig(config);
  const path = [];
  const list = [...tree];
  const result = [];
  const visitedSet = new Set(),
    { children } = config;
  while (list.length) {
    const node = list[0];
    if (visitedSet.has(node)) {
      path.pop();
      list.shift();
    } else {
      visitedSet.add(node);
      node[children] && list.unshift(...node[children]);
      path.push(node);
      func(node) && result.push([...path]);
    }
  }
  return result;
};

export const filter = (tree, func, config = {}) => {
  config = getConfig(config);
  const children = config.children;

  function listFilter(list) {
    return list
      .map((node) => ({ ...node }))
      .filter((node) => {
        node[children] = node[children] && listFilter(node[children]);
        return func(node) || (node[children] && node[children].length);
      });
  }

  return listFilter(tree);
};

export const forEach = (tree, func, config = {}) => {
  config = getConfig(config);
  const list = [...tree];
  const { children } = config;
  for (let i = 0; i < list.length; i++) {
    // func 返回true就终止遍历，避免大量节点场景下无意义循环，引起浏览器卡顿
    if (func(list[i])) {
      return;
    }
    children && list[i][children] && list.splice(i + 1, 0, ...list[i][children]);
  }
};

/**
 * @description: Extract tree specified structure
 */
export const treeMap = (treeData, opt) => {
  return treeData.map((item) => treeMapEach(item, opt));
};

/**
 * @description: Extract tree specified structure
 */
export const treeMapEach = (
  data,
  { children = "children", conversion }
) => {
  const haveChildren = Array.isArray(data[children]) && data[children].length > 0;
  const conversionData = conversion(data) || {};
  if (haveChildren) {
    return {
      ...conversionData,
      [children]: data[children].map((i) =>
        treeMapEach(i, {
          children,
          conversion,
        })
      ),
    };
  } else {
    return {
      ...conversionData,
    };
  }
};

/**
 * 递归遍历树结构
 * @param treeDatas 树
 * @param callBack 回调
 * @param parentNode 父节点
 */
export const eachTree = (treeDatas, callBack, parentNode = {}) => {
  treeDatas.forEach((element) => {
    const newNode = callBack(element, parentNode) || element;
    if (element.children) {
      eachTree(element.children, callBack, newNode);
    }
  });
};

/**
 * 构造树型结构数据
 * @param {*} data 数据源
 * @param {*} id id字段 默认 'id'
 * @param {*} parentId 父节点字段 默认 'parentId'
 * @param {*} children 孩子节点字段 默认 'children'
 */
export const handleTree = (data, id, parentId, children) => {
  if (!Array.isArray(data)) {
    console.warn("data must be an array");
    return [];
  }
  const config = {
    id: id || "id",
    parentId: parentId || "parentId",
    childrenList: children || "children",
  };

  const childrenListMap = {};
  const nodeIds = {};
  const tree = [];

  for (const d of data) {
    const parentId = d[config.parentId];
    if (childrenListMap[parentId] == null) {
      childrenListMap[parentId] = [];
    }
    nodeIds[d[config.id]] = d;
    childrenListMap[parentId].push(d);
  }

  for (const d of data) {
    const parentId = d[config.parentId];
    if (nodeIds[parentId] == null) {
      tree.push(d);
    }
  }

  for (const t of tree) {
    adaptToChildrenList(t);
  }

  function adaptToChildrenList(o) {
    if (childrenListMap[o[config.id]] !== null) {
      o[config.childrenList] = childrenListMap[o[config.id]];
    }
    if (o[config.childrenList]) {
      for (const c of o[config.childrenList]) {
        adaptToChildrenList(c);
      }
    }
  }

  return tree;
};

/**
 * 构造树型结构数据
 * @param {*} data 数据源
 * @param {*} id id字段 默认 'id'
 * @param {*} parentId 父节点字段 默认 'parentId'
 * @param {*} children 孩子节点字段 默认 'children'
 * @param {*} rootId 根Id 默认 0
 */
// @ts-ignore
export const handleTree2 = (data, id, parentId, children, rootId) => {
  id = id || "id";
  parentId = parentId || "parentId";
  // children = children || 'children'
  rootId =
    rootId ||
    Math.min(
      ...data.map((item) => {
        return item[parentId];
      })
    ) ||
    0;
  // 对源数据深度克隆
  const cloneData = JSON.parse(JSON.stringify(data));
  // 循环所有项
  const treeData = cloneData.filter((father) => {
    const branchArr = cloneData.filter((child) => {
      // 返回每一项的子级数组
      return father[id] === child[parentId];
    });
    branchArr.length > 0 ? (father.children = branchArr) : "";
    // 返回第一层
    return father[parentId] === rootId;
  });
  return treeData !== "" ? treeData : data;
};

/**
 * 校验选中的节点，是否为指定 level
 *
 * @param tree 要操作的树结构数据
 * @param nodeId 需要判断在什么层级的数据
 * @param level 检查的级别, 默认检查到二级
 * @return true 是；false 否
 */
export const checkSelectedNode = (tree, nodeId, level = 2) => {
  if (typeof tree === "undefined" || !Array.isArray(tree) || tree.length === 0) {
    console.warn("tree must be an array");
    return false;
  }

  // 校验是否是一级节点
  if (tree.some((item) => item.id === nodeId)) {
    return false;
  }

  // 递归计数
  let count = 1;

  // 深层次校验
  function performAThoroughValidation(arr) {
    count += 1;
    for (const item of arr) {
      if (item.id === nodeId) {
        return true;
      } else if (typeof item.children !== "undefined" && item.children.length !== 0) {
        if (performAThoroughValidation(item.children)) {
          return true;
        }
      }
    }
    return false;
  }

  for (const item of tree) {
    count = 1;
    if (performAThoroughValidation(item.children)) {
      // 找到后对比是否是期望的层级
      if (count >= level) {
        return true;
      }
    }
  }

  return false;
};

/**
 * 获取节点的完整结构
 * @param tree 树数据
 * @param nodeId 节点 id
 */
export const treeToString = (tree, nodeId) => {
  if (typeof tree === "undefined" || !Array.isArray(tree) || tree.length === 0) {
    console.warn("tree must be an array");
    return "";
  }
  // 校验是否是一级节点
  const node = tree.find((item) => item.id === nodeId);
  if (typeof node !== "undefined") {
    return node.name;
  }
  let str = "";

  function performAThoroughValidation(arr) {
    if (typeof arr === "undefined" || !Array.isArray(arr) || arr.length === 0) {
      return false;
    }
    for (const item of arr) {
      if (item.id === nodeId) {
        str += ` / ${item.name}`;
        return true;
      } else if (typeof item.children !== "undefined" && item.children.length !== 0) {
        str += ` / ${item.name}`;
        if (performAThoroughValidation(item.children)) {
          return true;
        }
      }
    }
    return false;
  }

  for (const item of tree) {
    str = `${item.name}`;
    if (performAThoroughValidation(item.children)) {
      break;
    }
  }
  return str;
};
